Frameless stereotaxy is widely used in the field of neurosurgery. It involves the quantitative determination of anatomical positions based on scan data taken from a CT, MRI or other scanning procedures to obtain three-dimensional scan data. Typically, the image scan data is placed in a computer to provide a three-dimensional database that may be variously used to provide graphic information. Essentially, such information is useful in surgical procedures and enables viewing a patient""s anatomy in a graphics display.
The use of stereotactic head frames is commonplace, for example, see U.S. Pat. No. 4,608,977 issued Sep. 2, 1986 and entitled, System Using Computed Tomography as for Selective Body Treatment. Such structures employ a head fixation device typically with some form of indexing to acquire referenced data representative of scan slices through the head. The scan data so acquired is quantified relative to the head frame to identify individual slices. Three-dimensional scan data has been employed to relate positions in a patient""s anatomy to other structures so as to provide a composite graphics display. For example, a space pointer (analogous to a pencil) might be directed at a patient""s anatomy and its position quantified relative to the stereotactic scan data. The space pointer might be oriented to point at an anatomical target and so displayed using computer graphics techniques. Such apparatus has been proposed, using an articulated space pointer with a mechanical linkage. In that regard, see an article entitled xe2x80x9cAn Articulated Neurosurgical Navigational System Using MRI and CT Images,xe2x80x9d IEEE Transactions on Biomedical Engineering, Volume 35, No. 2, February 1988 (Kosugi, et al.) incorporated by reference herein.
Further to the above considerations, the need for relating external treatment apparatus to a specific target arises in several aspects. For example, the need arises in relation to the treatment of internal anatomical targets, specifically to position and maintain such targets with respect to a beam or isocenter of a linear accelerator (LINAC) X-ray treatment machine. Thus, a need exists for methods of aligning beams, such as from a LINAC machine, to impact specific targets.
Generally, in accordance herewith, an optical camera apparatus functions in cooperation with a LINAC machine and a computer to enable treatment of a patient with a beam that is positioned and maintained on a specific target in a patient""s body. In an embodiment, the camera system is located in a known position with regard to the LINAC machine and to detect index markers at specific locations on a patient""s body. The markers employed during image scanning processes correlate to reference points for the scan data. Thus, by correlation, anatomical targets in the body, identified in the image scan data are effectively positioned with respect to the treatment beam from the LINAC machine identified by camera data. Essentially, data accumulation, transformation and processing operations serve to correlate scan data with camera data and thereby enable the desired positional relationships for patient treatment as well as providing an effective graphics display.